Page:Brinkley - Japan - Volume 8.djvu/93

 nearly approach the minerals called hälleflint, eurite, and petrosilex. With regard to the constituents of Arita porcelain, the mean of fifteen analyses made by Korschelt, Matsui, and Wurtz is as follows:—

No porcelain of similar composition is to be found among European wares. The closest approximation is shown by German porcelains, the composition of one class of which is felspar 20.3, clay substance 46.8, and quartz 31.8.

Mr. Korschelt has analysed the ashes obtained from the bark of the Distylicum racemosum, which, as has been said, are mixed with the glazing material of Arita porcelain. The result is as follows;

"The ashes, therefore," writes M. Korschelt, "consist of 61 per cent calcium carbonate, and also considerable quantities of calcium, potassium, magnesium, silicate, and phosphate. The faint greenish colour of the glaze obtained from these ashes is remarkable when we consider that they contain a small quantity of manganese."

The quantity of fuel consumed and the degree of heat developed in the ovens at Arita are points still demanding investigation. The practical experience of the workman is his guide, and he can only say that the process of baking occupies from four to five days, and that from first to last each article of porcelain passes through seventy-two hands.

The reader will perceive that the decoration described above is that known as blue under the glaze. Blue thus applied enters into the decoration of all the enamelled porcelain produced in Hizen, with the exception of certain wares of Kakiyemon and his imitators. As a distinguishing